[apalrd]

Unless you want to have 1 motor drive more than 1 wheel, integrating the drive motor and transmission into the crab pod might save space and possible a little weight too (less of that giant plate). We had 2:1 window motors last year for the rear pods on our robot (two motors for two wheels, the front two had Globe motors), and they worked very well. We also had ~3:1 reduction from window motors on a crab-drive system in 2005. It worked, although we didn't end up using it because moving sideways with a tetra led to instability. Also, you should be able to turn down the window motor coupler and fit a sprocket on it, then drill new holes and bolt it to the coupler, no need for that shaft on top. Then you can mount the potentiometer to the shaft mount on the coupler, with a keyed ring (to change size) and a set screw.